/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.dolphinscheduler.data.quality.flow.batch.transformer;

import org.apache.dolphinscheduler.data.quality.config.Config;
import org.apache.dolphinscheduler.data.quality.config.TransformerConfig;
import org.apache.dolphinscheduler.data.quality.enums.TransformerType;
import org.apache.dolphinscheduler.data.quality.exception.DataQualityException;
import org.apache.dolphinscheduler.data.quality.execution.SparkRuntimeEnvironment;
import org.apache.dolphinscheduler.data.quality.flow.batch.BatchTransformer;

import java.util.ArrayList;
import java.util.List;

/**
 * WriterFactory
 */
public class TransformerFactory {

  private static class Singleton {
    static TransformerFactory instance = new TransformerFactory();
  }

  public static TransformerFactory getInstance() {
    return Singleton.instance;
  }

  public List<BatchTransformer> getTransformer(SparkRuntimeEnvironment sparkRuntimeEnvironment, List<TransformerConfig> transformerConfigs) throws DataQualityException {

    List<BatchTransformer> transformers = new ArrayList<>();

    for (TransformerConfig transformerConfig : transformerConfigs) {
      BatchTransformer transformer = getTransformer(transformerConfig);
      if (transformer != null) {
        transformer.validateConfig();
        transformer.prepare(sparkRuntimeEnvironment);
        transformers.add(transformer);
      }
    }

    return transformers;
  }

  private BatchTransformer getTransformer(TransformerConfig transformerConfig) throws DataQualityException {
    TransformerType transformerType = TransformerType.getType(transformerConfig.getType());
    Config config = new Config(transformerConfig.getConfig());
    if (transformerType != null) {
      if (transformerType == TransformerType.SQL) {
        return new SqlTransformer(config);
      }
      throw new DataQualityException("transformer type " + transformerType + " is not supported!");
    }

    return null;
  }

}
